Friday, September 11, 2015

As governments and industries expand their
use of high-decibel seismic surveys to explore the ocean bottom for
resources, experts from eight universities and environmental
organizations are calling for new global standards and mitigation
strategies.

Their goal is to minimize the amount of sound the surveys produce and reduce risks the surveys and other underwater human noise pollution poses to vulnerable marine life.

Firms and agencies conducting the surveys would benefit from these
new measures, the experts assert, because instead of having to navigate
an assortment of rules that vary by nation or region, they would have a
uniform set of standards to follow.
"In recent years, we've seen an increase in the use of seismic surveys for oil and gas exploration
and research, and for establishing national resource claims on
ever-larger geographic scales. Surveys are now occurring in, or proposed
for, many previously unexploited regions including parts of the Arctic
Ocean and off the U.S. Atlantic coast," said Douglas P. Nowacek, an
expert on marine ecology and bioacoustics at Duke University.
"The time has come for industries, governments, scientists and
environmental organizations to work together to set practical guidelines
to minimize the risks," he said.
Nowacek and his colleagues published their recommendations in a peer-reviewed paper today (Sept. 1) in the journal Frontiers in Ecology and the Environment.

Two sperm whales "fluke-up" near the Texas A&M Research Vessel Gyre.

Seismic survey impulses are among the loudest noises humans put into
the oceans, and in some cases can be detected more than 2,500 miles
away.
The increase in ocean noise they cause can mask sounds whales and
other species rely on to communicate, navigate, find food or avoid
predators.
Long-term exposure to the noise can also lead to chronic
stress and disorientation in animals, and auditory damage.
To reduce these risks, the new paper recommends that ocean noise be
recognized globally as a pollutant - something the European Union
already recognizes - and managed through a revision to the existing
International Convention on the Prevention of Pollution from Ships.
This
will allow the establishment of consistent, scientifically based
standards and monitoring programs for ocean noise levels, Nowacek said.
Using empirical data from this monitoring and from ongoing field
studies the convention would support, scientists could more thoroughly
assess surveys' cumulative long-term impacts on marine life and identify
areas where seismic activities should be prohibited or temporarily
limited to protect important habitats or vulnerable populations.

A rising tide of man-made noise is disrupting the lives of marine animals.

Wider use of multi-client surveys could also cut risks.
By collecting
data simultaneously for two or more firms or agencies, these surveys
significantly reduce the number of surveys required in a region, without
forcing clients to share proprietary data. They've been successfully
tested in Norway.

A rare and endangered blue whale offshore near Long Beach, Calif.

Dave McNew/Getty Images

Emerging technologies could further reduce a survey's acoustic
footprint.
Many of these technologies, including the marine vibrator -
which conducts surveys using a steady pulse of low-pressure sound waves
over a longer period - are "not that far away from industrial scale
use," Nowacek said.
The need to implement these new protective measures and scale up
these technologies is urgent, he stressed. As sea ice in the Arctic
Ocean rapidly diminishes, bordering nations are eyeing new underwater
oil and gas exploration and research prospects there. Increased activity
is also proposed for lower latitudes.
"Survey permits are now being considered for oil and gas exploration
along the U.S. East Coast that would allow surveys to occur as close as
three miles from the coast. However, the current draft of the U.S.
Bureau of Ocean Energy Management's five-year plan for East Coast oil
and gas exploration
allows oil and gas lease areas to be no closer than 50 miles offshore.
That's a pretty big difference," Nowacek said. "While gathering some
data from beyond a lease area is necessary, allowing these industries to
survey to within three miles of the coast is excessive."